Vibration damping has taken many different forms. U.S. Pat. No. 3,663,116 discloses a structure intended to damp torsional vibrations in a boring bar with steel outer and inner tubular members welded together at the mounting end and separated by a layer of rubber. U.S. Pat. No. 3,838,936 discloses a boring bar holder which is adjustably damped by two axially compressible rubber spring members. U.S. Pat. No. 4,491,044 discloses a boring bar holder on a turret with a facial relief and a seal creating a closed damping chamber which may be filled with oil or with a viscoelastic material. U.S. Pat. No. 3,800,380 discloses a viscous damped cutting tool by means of a soft inner core inside the hard surface cutting tool. U.S. Pat. No. 3,544,415 discloses alternate plates of steel and relatively thick plates of rubber used as bearing pads for a bridge subject to elongation. U.S. Pat. No. 4,278,726 discloses a leaf spring formed from laminations of elastomer and rigid layers, including metal. U.S. Pat. No. 4,447,181 discloses a boring bar mount with a rubber pad compressed in a recess with metal-to-metal engagement on the mounting face surrounding the rubber pad.